accelerated testing validation - us department of energy · 2013-05-02 · u.s.doe fct program amr...

U.S.DOE FCT Program AMR and Peer Evaluation Meeting May 15, 2013

Accelerated Testing Validation

Rangachary (Mukund) Mukundan Los Alamos National Laboratory

May 15th 2013

This presentation does not contain any proprietary, confidential, or otherwise restricted information

Project ID # FC016


Project Overview Barriers

• Project Start Date – August 2009

• Project Duration – 4 Years (End: Sept ’13)

• ≈ 90% complete

Fuel cells: 2011 Technical Plan A. Durability

Automotive 5,000 hours (10% degradation) Stationary 2017 : 40,000 hours (20% degradation) 2020 : 60,000 hours (20% degradation) Bus 1016 : 18,000 hours

Accelerated testing protocols need to be developed to enable projection of durability and to allow for timely iterations and improvements in the technology.

• Total project funding – 4 Years : $4,159,790 – DOE Cost : $4,000,000 – Cost Share : $159,790

• Funding for FY12/FY13 LANL $ 397k, 750k + Partners (Industry)

Other National Labs $ 300k, 250k FY12/FY13 Total $ 697k,1000k

• Ballard Power (System Integrator) • Ion Power (Materials Supplier) • ORNL (Metal Bipolar Plates) • LBNL (Modeling)

Timeline

Partners

Budget


Objectives/Barriers - Relevance

The objectives of this project are 3-fold 1. Correlation of the component lifetimes measured in an AST to real-world behavior of that component. 2. Validation of existing ASTs for Catalyst layers and Membranes 3. Development of new ASTs for GDLs, bipolar plates and interfaces

Technical Targets Automotive : Durability with cycling: 5,000 hours (2010/2015): 2005 Status (2000 hours for stack and 1000 hours for system) Stationary : Durability: 40,000 hours (2011): 2005 Status = 20,000 hours Bus Data : 18,000 hours (2016); 25,000 hours (ultimate); Status = 12,000 hours. Importance of Accelerated Stress Test (AST) • Allows faster evaluation of new materials and provides a standardized test to benchmark existing materials • Accelerates development to meet cost and durability targets • Different ASTs are available (DOE-FCTT, USFCC and JARI)

– Lack of correlation to “Real World” Data – No tests available for GDLs and other cell components – Value of combined vs individual tests


Approach

BPS Bus Fleet Data • Voltage degradation distribution data from P5 fleet & HD6 Module

• Cell Data (36 Cells) • MEA Characterization (108 MEAs)

LANL Drive Cycle Testing • Automotive drive cycle testing • RH, Temp, Pressure effects

Field Data

Statistical Correlation • Relate field and AST data to

physical attribute change • Good correlation if AST slope

similar to “Real World Data” slope

Physical Attribute Change

AST Data

Voltage Loss

Materials • BPS provides materials used in Bus Stack • W. L. Gore provides commercial MEAs • Ion Power provides custom MEAs • SGL carbon provides commercial GDL materials • ORNL provides metal bipolar plates

LANL performs DOE-FCTT ASTs Develops GDL, bipolar plate ASTs

Characterization Fuel Cell Performance VIR, Impedance, HelOx, Modeling Catalyst • ECSA, Mass activity, particle size, layer thickness, composition, loading Membrane Cross-over, shorting resistance, HFR, thickness GDL •Impedance, Hydrophobicity

Goals • Recommend improved catalyst and membrane ASTs that correlate to real world data • Recommend ASTs for GDL and bipolar plate materials • Co-ordinate efforts with FCHEA and USDOE-FCTT


Approach - Milestones

Begin 08/09

End 09/13 Milestones

M1: Complete failure analysis of LANL AST samples (Complete 12/2011) M2: Developed improved multi-model and multi-variable fitting algorithm. (Complete 03/2013) M3: Complete failure analysis of Ballard samples (Complete 04/2012) M4: Complete AST testing on a high SA and a low SA carbon (Complete 04/2012) M5: Delivery of AST, field, and virgin membranes to LBNL for testing. (Complete 12/2012) M6: Complete failure analysis of LANL AST samples including 3 different catalyst layers on DuPont XL membranes. (Complete 12/2012) M7: Deliver a total of 50 MEAs customized for 2 different MEA types (standard, FCT, 50 cm2 and 50 cm2 for GM/RIT hardware) (Complete 04/2013) M8: Complete drive cycle testing on 3 different membranes and 3 different catalyst layers (33% complete) M9: Propose validated GDL, membrane and start/stop ASTs (80% complete) M10 : Final Statistical correlation of AST and Bus data to material property and AST lifetimes to drive cycle of materials with varying lifetimes

M9/M10 09/13

M5/M6 12/12

M1 12/11

M2 03/12

M3/M4 04/12

M7 04/13

M8 06/13


Materials Used • GoreTM MEAs (AST: 2010 AMR, F/A: 2011 AMR)

– GoreTM Primea® MESGA MEA A510.1/M720.18/C510.2 – GoreTM Primea® MESGA MEA A510.2/M720.18/C510.4 – GoreTM Primea® MESGA MEA A510.1/M710.18/C510.2

• Ballard P5 and HD6 MEAs (AST: 2011 AMR, F/A: 2012 AMR) • Ion Power MEAs (AST, F/A: 2012 AMR)

– DuPont XL membranes – Tanaka Catalysts

• TEC10E50E, TEC10E40E, TEC10E20E (High Surface area carbon 50 wt%, 40 wt% and 20 wt% Pt)

• TEC10V40E, TEC10V20E (Vulcan carbon 40 wt%, 20 wt% Pt) • TEC10E40EA Low Surface area carbon 40 wt% Pt

• GDL – SGL 24BC (5% PTFE-substrate/23% PTFE MPL) – Varying PTFE content and substrate porosity

• Bipolar plates – G35 and Ni50Cr: Corrosion testing (coupons) and fuel cell testing (plate) – No degradation observed in short term testing in MEA (awaiting input from other LANL

durability project)

Accomplishments /Progress

M710 : Discontinued product. Lower chemical and mechanical durability sample

M720 : technology circa 2005. Higher chemical and mechanical durability sample

F/A = Failure Analysis


Field Data • History of P5 Stacks are as follows:

– PE4 with 2,769 hours of operation – PE22 with 3,360 hours of operation – PE24 with 2,597 hours of operation – All 3 buses operated in Hamburg for their life – Data over a sample stretch of 1-2 hours were analyzed to define

performance degradation – 8-10 time periods per stack were analyzed to ensure enough

points to develop a good average performance degradation rate

• HD6 Stack is designated as follows: – SN5096 with 6,842 hours of operation – Stack was system tested in lab under Orange County Transit

Authority (OCTA) cycle – Due to pull outs of MEAs from stack will have failure analysis

(FA) data at ~2,400 hours, 4,300 hours and 6,842 hours


Presented in 2011/2012 AMR


Drive Cycle Testing

Use 100% H2 instead of 80% H2 Only one station capable of RH control (bottle = 90oC, adjust dry and wet flows) Also performing cycles at the high RH conditions (Wet Cycling)

0.00

0.20

0.40

0.60

0.80

1.00

1.20

1.40

1.60

1.80

2.00

0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34

Time (minutes)

US DRIVE Wet/Dry Drive Cycle 2 cycles Shown

Cell Voltage (volts)

Current Density (amps/cm2)

Hydrogen Flow (lpm)

Air Flow (lpm)

H2 Humidity (%RH/100)

Air Humidity (%RH/100)



Potential Cycling AST

• Pt particle size growth observed in both TEM and XRD • Correlates with decreasing ECSA

• Observed in both electro-catalyst (potential cycling) and carbon corrosion (high potential hold) AST

• Mass activity, voltage loss, and increased impedance in kinetic region observed

• 40% ECSA loss corresponds to approx. 20 mV voltage loss

0

0.005

0.01

0.015

0.02

0.025

0.03

0.035

0.04

0.045

0.05

0

10

20

30

40

50

60

70

80

90

0 5000 10000 15000 20000 25000 30000 35000

Volta

ge L

oss @

0.8

A/c

m2 (

V)

% E

CSA

Loss

# of Potential Cycles

TEC10E20E (0.2mg/cm2) ECSA

TEC10E20E (0.2mg/cm2) (Rep), ECSA

TEC10E40E (0.4mg/cm2), ECSA"

TEC10E20E (0.2mg/cm2), Voltage

TEC10E20E (0.2mg/cm2) (Rep), Voltage

TEC10E40E (0.4mg/cm2), Voltage

0

10

20

30

40

50

60

70

80

0 5 10 15

ECSA

(m2 /

gm)

Average Pt Particle Size (nm)

Cathode ECSA vs Pt Particle size Fresh Baseline

Potential Cycling

Potential Hold

Drive Cycle 1

Drive Cycle 2

Fresh (Differentcarbons)



Correlation of AST and Drive Cycle Accomplishments /Progress

• 30,000 cycles ≈ 2000 hours of bus operation (Both P5 and HD6)

• 30,000 cycles ≈ 850 hours of US DRIVE Drive-Cycle

• 30,000 cycles ≈ 500 hours of wet drive cycle

• 5000 hours ≈ 175,000 cycles • Need > 30,000 cycles for 5000

hour automotive durability

0

10

20

30

40

50

60

0 20000 40000 60000 80000

% E

CSA

Loss

# of Potential Cycles

AST

US Drive : Drive cycle

•Pt particle size increase. • Consistent with potential cycling AST • Larger Pt growth in drive cycle samples than AST samples 6.5 nm after 30,000 cycles 9.5 nm to 11.5nm after 1.2 V AST 9.4 nm after 2000+ hours wet/dry cycle 7.5 nm after 1200 hours wet cycle 5.6 nm after 300 hours wet cycle

Catalyst AST

30000 Cycles Drive Cycle

30000 cycles

C510.2 53.80% 53.7%, 54.3%

C510.4 46.3%, 46.8% 46.60%


Carbon corrosion at low potentials

0

25

0 0.5 1 1.5 2

Corr

osio

n ra

te (μ

g C cm

-2 h

-1)

Time (min)

EA 1.3 V holdEA 1.2 V holdEA 1.1 V holdEA 1.0 V holdEA 0.9 V hold

0255075

100125150175200225250275300325350375400

0 0.5 1 1.5 2

Corr

osio

n ra

te (μ

g C cm

-2 h

-1)

Time (min)

E 1.3 V holdE 1.2 V holdE 1.1 V holdE 1.0 V holdE 0.9 V hold

0

5

10

15

20

25

30

35

40

45

50

0.6 0.8 1 1.2 1.4

Corr

osio

n ra

te (μ

g C cm

-2 h

-1)

Cell potential (V)

1.4 V UPL

EA 0.6 to 1.4 V @ 5 mV/s

EA 0.8 to 1.4 V @ 5 mV/s

EA 1.0 to 1.4 V @ 5 mV/s

Significant carbon corrosion observed @ 0.9 V for high surface area carbon Corrosion can be significantly accelerated using higher upper potentials and cycling instead of holds FCTT adopting 1 – 1.5 V cycling



Drive Cycle: Catalyst degradation (HSAC)

Pt band observed on cathode side of MEA. Band clearly visible after 2000 hours with high (0.4 mg.Pt/cm2) loaded catalyst 860 hours results in 10% thinning of catalyst layer, 1200 hours results in 25 % thinning and 2000+ hours in 50% thinning

860 hrs wet drive cycle 1224 hrs wet drive cycle HSAC : High surface area carbon



Carbon Corrosion : Correlations

• Large spatial variations in corrosion due to start/stop

• Longer times at air/air potential results in greater corrosion

• Pt particle size growth much larger during start/stop tests.


0

10

20

30

40

50

60

0 10 20 30 40 50

Chan

ge in

ele

ctro

de th

ickn

ess (

%)

Hours at 1.2 V

Cathode thickness decrease at 1.2 V hold 690 Stops Air Outlet 690

Stops Air Inlet

577 Starts Air Outlet

577 Starts Air Inlet

0

10

20

30

40

50

60

70

0 20 40 60 80 100 120

Chan

ge in

Pt s

ize (%

)

Hours at 1.2 V

Pt growth at 1.2 V hold

577 Starts Air Outlet

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 100 200 300 400 500 600 700 800 900 100011001200130014001500

Volta

ge (V

), C

urre

nt D

ensi

ty (A

/cm

2 )

Time (seconds)

Voltage (V)

Current Density (A/cm2)

Hydrogen / Air

Air / Air

single cycle = 800 seconds

Hydrogen / Air


Voltage loss Breakdown Analysis Accomplishments /Progress

• LBNL modeling used for VLB • Catalyst coarsening causes slight increase in cathode

kinetic loses • Little Ohmic changes • Major loss is cathode transport losses consistent with

collapse of cathode structure • Will be compared with drive cycle testing using multiple

catalyst layers to get statistical correlations

0

0.2

0.4

0.6

0.8

1

1.2

0 0.5 1 1.5 2 2.5

Cell

Pote

ntia

l[V]

Current Density [A/cm2]

Xptal 100 hours

Model Fit

Xptal - Initial

Model Initial

-

200

400

600

800

1,000

1,200

1,400

Volta

ge (m

V)

-

200

400

600

800

1,000

1,200

1,400

Volta

ge (m

V)

AMR 2012

BOL EOL


-0.10

0.10.20.30.40.50.60.70.8

0 5 10 15 20 25

Ioni

c Cu

rren

t (A)

Nodes from Membrane to GDL

Initial

Aged

Voltage loss Breakdown Analysis Similar performance could be achieved

for different distribution of resistance

Manual supervision is required to allot appropriate weight to the various resistances

Reaction distributions in the catalyst layers need adjustment

Mass transport losses in ionomer, catalyst layer pores, GDL

- 200 400 600 800

1,000 1,200 1,400

Pote

ntia

l (m

V)

-

200

400

600

800

1,000

1,200

1,400

Pote

ntia

l (m

V)


Similar EOL Performance : Needs further refining of mass transport losses


00.20.40.60.8

11.21.4

0 0.5 1 1.5

Imag

inar

y Im

peda

nce

(Ohm

cm

2 )

Real Impedance (ohm cm2)

Model

Experimental

0

0.2

0.4

0.6

0.8

1

1.2

1.4

0 0.5 1 1.5

Imag

inar

y Im

peda

nce

(Ohm

cm

2 )

Real Impedance (ohm cm2)

Good agreement in the kinetic region

The second capacitance loop is associated with channel effects

Modeling impedance gives an accurate determination of individual resistance

Simultaneous fitting of Air and HelOx data at different current densities

Voltage loss Breakdown Analysis Accomplishments /Progress


Membrane ASTs Accomplishments /Progress

0

5

10

15

20

25

0 5000 10000 15000 20000 25000

Cros

s Ove

r (m

A/cm

2)

# of RH Cycles

N212Sample ASample BBallard HD6Ballard P5Dupont XL

0

5

10

15

20

25

0 100 200 300 400 500

Cros

s Ove

r (m

A/cm

2)

Time (Hours)

Ballard HD6Ballard P5Sample ASample BDupont XL

RH Cycling OCV

0

5

10

15

20

25

0 5000 10000 15000 20000 25000

Cros

s ove

r (m

A/cm

2)

# Cycles

RH Cycling in H2/Air (80C) Ballard HD6Ballard P5N212Dupont XLSample ASample B

20,000 cycles = 1333 hrs

333 hrs 1000 hrs

• RH cycling test does not have ability to distinguish between most PFSA membranes

• OCV testing too severe for bus applications

• Combined mechanical/chemical AST has ability to distinguish between MEAs, needs further acceleration.

AMR 2012


Drive Cycle: Membrane failure modes

0.0

5.0

10.0

15.0

20.0

0 500 1,000 1,500 2,000 2,500

Cros

sOve

r (m

A/cm

2 )

Total Hours

Crossover

Sample B (Wet/Dry)

Sample A (Wet/Dry)

Sample A (Wet)

Sample A (Wet - RIT)

• Both Wet/Dry and Wet cycles result in crossover increases and membrane failure

• Little thinning observed in membrane (< 10% to none) • Consistent with field data from buses • Not compatible with OCV AST.

Baseline: 1200+ hours wet cycling Baseline: 850+ hours wet cycling



AST/Field correlation - Membrane

P5 sample after H2/Air RH cycling AST HD6 Field Sample

P5 Field Sample

•! RH cycling data being analyzed •! Membrane failure time decreases with

increased time > 0.8 V •! Membrane failure time increases with

increasing inlet RH



Membrane Degradation

SAXS reveals similar membrane degradation in field samples as those aged under the combined mechanical/chemical cycle.

The OCV aging is too severe and the RH cycling is too benign.

M-R&K+-BJ#

6=># N+c0+J#

]a&4,.$"56&^-ACF/+AFB#

'"X#1#5)& 5+,+BF=#

@C-,+AFB&/78& 5+,+BF=# D:1#&7#M#1#&

]a4&g&h49&^-ACF/+AFB#<

@C-,+AFB#5+,+BF=# 5+,+BF=#



Develop GDL AST Accomplishments /Progress

Collaborative development with UTC to examine observed field GDL degradation GDLs aged at 95oC in 30% H2O2 (Original procedure from Decode project, Peter Wilde: SGL Carbon) Simulates loss of hydrophobicity Substrate pore volume increases Low current/ low RH performance similar Degradation in high current/high RH performance

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0 1 2 3 4 5

Volta

ge (V

)


100% RH Fresh H2/HelOx

7hrs H2/HelOx

15 hrs H2/HelOx

0

0.05

0.1

0.15

0.2

0.25

0 0.1 0.2 0.3 0.4 0.5

-Imag

inar

y Im

peda

nce

(Z")

Ohm

-cm

2

Real Impedance (Z) Ohm-cm2

0.8A/cm2 (100% RH) 15 hrs H2/Air

7hrs H2/Air

Fresh H2/Air

0

0.05

0.1

0.15

0.2

0.25

0.3

0.35

0.4

0.45

0.5

0 0.2 0.4 0.6 0.8 1

-Imag

inar

y Im

peda

nce

(Z")

Ohm

-cm

2

Real Impedance (Z) Ohm-cm2

1A (100% RH) 15 hrs H2/Air

7hrs H2/Air

Fresh H2/Air

AMR 2012


Drive Cycle: GDL Failure mode

• Mass transport issues. Catalyst layer/GDL flooding • Slightly higher flow rates can easily restore performance to almost

BOL levels

0.000.100.200.300.400.500.600.700.800.901.001.101.201.30

0 1 2 3 4 5 6 7 8 9 10

Volta

ge (V

)/Cu

rren

t Den

sity

(A/c

m2)

Time (minutes)

Ten EOL (600 hours) Cycles (113% RHs, 101 KPa-abs) for SGL-25BN Cell

Current Density (A/cm2)Cell Voltage (2.0 lpm Air, 2.0 stoich)Cell Voltage (1.89 lpm Air, 1.9 stoich)Cell Voltage (1.8 lpm Air, 1.8 stoich)



Mass transport losses : HSAC

3040 hours of drive cycle 1224 hours of wet drive cycle

Significant increase in mass transport losses GDL degradation? Difficult to de-couple catalyst layer effects

HSAC : High surface area carbon



Mass transport losses : LSAC

• Mass transport losses : Stopped Wet Drive cycle testing @ 382 hours. (Cannot sustain high currents, Cell Reversal)

• Little thinning observed. • 30-35% ECSA loss with 80% increase in Pt particle size

LSAC : Low surface area carbon (Graphitized)

0.25

0.35

0.45

0.55

0.65

0.75

0.85

0.95

0.00 0.50 1.00 1.50 2.00 2.50

Volta

ge


LANL H2/Air Polarization Curves

BC 0 HoursBC 164 HoursBC 328 HoursBC 389 Hours

0.00

0.05

0.10

0.15

0.20

0.00 0.05 0.10 0.15 0.20 0.25 0.30 0.35 0.40

Imag

inar

y Im

ped.

(Z')

ohm

-cm

2

Real Imped. (Z) ohm-cm2

Impedance for 70 Amp (1.4 A/cm2)

BOL H2-Air

EOL H2-Air

BOL H2-HelOx

EOL H2-HelOx

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0.00 0.10 0.20 0.30 0.40 0.50

Imag

inar

y Im

ped.

(Z')

ohm

-cm

2

Real Imped. (Z) ohm-cm2

Impedance for 10 Amp (0.20 A/cm2)

BOL H2-Air

EOL H2-Air

BOL H2-HelOx

EOL H2-HelOx



Drive Cycle Testing: Varying GDLs

0

0.2

0.4

0.6

0.8

0 5 10

Volta

ge (V

)

Time (mins)

SGL 25BC GDL BOL : BCEOL : BC (389 hrs)

0

0.2

0.4

0.6

0.8

0 2 4 6 8 10

Volta

ge (V

)

Time (mins)

SGL 25BN GDL BOL : BN

EOL : BN (600 hrs)

0.40

0.50

0.60

0.70

0.50 1.00 1.50 2.00 2.50

Volta

ge


H2/Air Polarization Curves BC 0 HoursBC 328 HoursBN 0 hrsBN 319 hrs

Same MEA: Similar Catalyst Degradation and ECSA loss XPS confirms increase in CxOy peaks in aged GDLs (AST, Drive cycle, ex situ aged)

0.00

5.00

10.00

15.00

20.00

25.00

30.00

35.00

40.00

0 100 200 300 400 500 600 700

ECSA

loss

(%)

Time (hours)

ECSA (BC vs BN)

BC: % loss ECSA

"BN: % loss ECSA"



Collaborations LANL (Rangachary Mukundan, Rodney Borup, John Davey, David Langlois, Dennis Torraco, Roger Lujan, Dusan Spernjak, Joe Fairweather and Fernando Garzon) • Co-ordinate project; Perform all ASTs and Drive cycle testing; Materials Analysis of BOL and EOL materials

Ballard Power Systems (Paul Beattie, Greg James, Dana Ayota) • Analyze Bus Data; Deliver BOL MEAs used in Buses; Analysis of MEAs

LBNL (Adam Weber, Siva Balasubramanian, Wonseok Yoon) • Detailed Voltage loss break-down; Statistical correlation of materials properties to lifetimes and AST metric loss of materials with differing durabilities

Ion Power (Steve Grot) ORNL (Mike Brady, Karren More) Deliver MEAs with varying durability Deliver metal bipolar plates/TEM W. L. Gore and Associates Inc., and SGL Carbon (materials suppliers) Durability working group (Start/Stop protocol) Nancy University (Start/Stop segmented cell testing) Olivier Lottin (PI)


Summary/Future Work - I • Initial AST (electrocatalyst, catalyst support, membrane

chemical and mechanical) performed • Baseline materials from W.L. Gore, P5 and HD6 and Ion Power

MEAs with three different catalyst supports • Failure analysis from all ASTs

• Bus Data analysis completed on P5 and HD6 bus stacks • Data on number of RH cycles and potential cycles from the buses

are being analyzed

• Automotive drive cycle (FCTT) testing in progress on GM-RIT and quad-serpentine hardware • Baseline materials completed • Ion Power materials initiated. • GDL degradation issues have been addressed (need to be

quantified) • Start/Stop will not be incorporated in drive cycle. The Durability

Working Group protocol for start/stop is being studied separately.


Summary/Future Work - II • Start/Stops performed at Nancy University

– Large spatial variations make average correlations difficult – Extremes will be studied

• Voltage loss break down modeling being refined • Down the channel effects being added to simultaneously fit

impedance data • Models to be refined for better fit at > 1 A/cm2 (GDL transport)

• NEW ASTs • GDL AST proposed. Surface oxidation of carbon observed in all

samples. Degradation mechanism similar in drive cycle, AST and ex situ samples

• Membrane mechanical/chemical AST found to reliably simulate field and drive cycle failure modes

• 1 to 1.5 V carbon corrosion AST to be evaluated

• Compile all data in a Web site in addition to publications


Acknowledgements

Nancy Garland (DOE – EERE – Fuel Cell Technologies – Technology Development Manager) Dimitrios Papageorgopoulos Fuel Cell Tech Team (Craig Gittleman, Jim Waldecker and Balsu Lakshmanan) for guidance on ASTs W. L. Gore and Associates (MEAs) SGL Carbon (GDLs)


Technical Backup Slides


1-D simplified model

!! 8+#&F:%#$&"-&BO'V&-)#(%,&-)()#&

!! /%%&"5&)1(5-"#5)&)#1F-&):&%:&"FG#%(5.#&&

!! D:%#$&"-&3G%()#%&(5%&$#M#1(6#%&H1:F&T:1i&"5&:)+#1&;<I;&G1:d#.)-&

!! !"Q56&G(1(F#)#1-&%#G#5%&:5&/78V&23)&(1#&),G".($$,&#X#.NM#&)1(5-G:1)&.:#j."#5)-V&-31H(.#&(1#(&J"H&5:)&F#(-31#%LV&!"#R&

Steady-state solution Complex function

k::5&(5%&f#2#1&lA7&(U'V&<B==Z&

f#2#1&l*7&B@UV&UK@K&

f#2#1&(5%&I#TF(5V&"5&$!%&#!'()*'+("!,&(-.'+/*!-&)0'&)'12+''34!-'5!--.V&*(%%"-:5&(5%&*1:F"-$:TV&A%-V&&&&&&&7G1"56#1V&BUZOB@>&JK==@LR&


"! Operating/test conditions

"! Cyclic voltammetry (active area)

"! Electrochemical impedance

"! Polarization curve

"! VLB "! Sensitivity to

model fit parameters

"! Look for controlling dimensionless groups

"! 1-D simple model "! Modify to calculate/fit

EIS profiles and polarization curves using physical equations

"! Fit parameters to data

Inputs Outputs Model

1-D simplified model

!! l(.:2"(5&F()1"e&H1:F&)+#&-)#(%,&-)()#&F:%#$&"-&3-#%&):&#-NF()#&)+#&"FG#%(5.#&"5&)+#&H1#c3#5.,&%:F("5&


Tech Team Protocol (Pt Catalyst)


Tech Team Protocol (Catalyst Support)


Tech Team Protocol (Membrane/Chemical)


Tech Team Protocol (Membrane/Mechanical)

accelerated testing validation - us department of energy · 2013-05-02 · u.s.doe fct program amr...

Documents